Topic 4.4: Climate Change

Question 1

Definition of atmosphere

Answer 1

Collection of gases above Earth’s surface

Question 2

Function of atmosphere

Answer 2

Retain heat at night and prevent fluctuations in temperatures

Question 3

Function of greenhouse gases

Answer 3

Trap and hold heat within the atmosphere

Question 4

Factors that affect the extent of warming impact of a gas

Answer 4

a) Ability to absorb long-wave radiation

b) Concentration within the atmosphere

Question 5

Classification of gases according to their significance

Answer 5

a) High (H2O / CO2)

b) Low (CH4 / NOx)

Question 6

Definition of Greenhouse Effect

Answer 6

Natural process whereby the atmosphere behaves like a greenhouse to trap and retain heat

Question 7

Significance of Greenhouse Effect

Answer 7

a) Ensures the Earth maintains a moderate temperature needed by organisms to maintain life processes
b) Without it, Earth’s temperature would drop significantly at night in the absence of direct sunlight

Question 8

Process of Greenhouse Effect

Answer 8

a) Incoming radiation from the sun is short-wave (UV) radiation
b) This radiation may be emitted by the Earth as long-wave (IR) radiation
c) Greenhouse gases absorb and re-emit this IR radiation as heat.
d) Heat is trapped inside the atmosphere.

Question 9

Human activities that increase greenhouse gas emission

Answer 9

a) Deforestation
b) Farming / Agriculture
c) Combustion (Main cause)

Question 10

Explanation of the effect of deforestation in greenhouse gas emission

Answer 10

Removal of trees means that less CO2 is removed from the atmosphere via photosynthesis

Question 11

Explanation of the effect of farming in greenhouse gas emission

Answer 11

a) Removal of trees for cattle grazing

b) Ruminant cattle produce CH4

Question 12

Explanation of the effect of combustion in greenhouse gas emission

Answer 12

a) When fossil fuels are combusted to produce energy, CO2 is released as a byproduct.
b) Increased reliance on fossil fuels has resulted in an increase in CO2 levels.

Question 13

Role of greenhouse gases in climate change

Answer 13

As these gases trap heat, increases in greenhouse gas concentrations should correlate with an increase in global temperatures

Question 14

Examples of the effects in climate of an increase in greenhouse gas concentrations

Answer 14

Some areas become more drought, while others will be more prone to heavy rainfall

Question 15

Correlational studies between global temperatures and CO2 concentrations

Answer 15

a) There is a strong positive correlation between CO2 concentrations and temperature
b) There have been fluctuating cycles of CO2 concentration which correlate with global warm and ice ages.
c) While correlation does not equal causation, there is mounting evidence to suggest that CO2 emissions are linked to global temperature changes.

Question 16

Process of ocean acidification

Answer 16

a) Oceans absorb atmospheric CO2
b) Dissolved CO2 combines with H2O to form carbonic acid, increasing oceans’ pH
c) H+ concentrations will increase and combine with free CO3 ions to form HCO3-

Question 17

Consequences of ocean acidification

Answer 17

a) Decrease in viability of coral reefs and molluscs
b) Loss of shoreline protection and habitat, altering coastal ecosystems.
c) Loss in revenue from tourism and food industries
d) Flourishment of invasive species of algae

Question 18

Climate has changed in the past and current trends merely reflect the Earth’s natural climatic cycle

Answer 18

A: Experimental data shows several changes in climate over the last 400,000 years.
C: Climate changes occur naturally. but not as abruptly as what is seen currently

Question 19

Climate change is being caused by solar activity and the effect of greenhouse gas emissions is negligible

Answer 19

A: Warmer temperatures may be caused by an increase in solar irradiance.
C: Over the last 35 years, the sun has shown a cooling trend.

Question 20

Certain changes in climate conditions cannot be linked to greenhouse gas emissions

Answer 20

A: Global sea levels began to increase before greenhouse gas emissions increased following industrial revolution
C: Rate at which sea levels have risen in the past 30 years is greater than seen in the last 200 years.

Question 21

Variability between prediceted climate change models means that such models are unreliable

Answer 21

C: All models predict an increase in average global temperatures over the next 100 years.

Question 22

Increases in greenhouse gas concentrations in the atmosphere will not be enough to cause climate change.

Answer 22

C: The reason why CO2 is so important to the environment is because there is so little of it.
C: Living things require constant internal environments.